iirc, 1 bar is 15psi and 1.2 bar (as in overboost) is about 17psi, and that's what I see on my dash meter (although its accuracy has been questioned it does at least show a consistent difference). That's also what is listed in my car manual.

 

TClay

Thanks for the info. This helps a little bit. However who previous owned isn't really as important as how the car was driven prior to taking ownership. I'm sure your glad that with your car swap M6/997TT

 

Speed21 please read my previous post. After doing some local research this is what I have found. Typically in the past though keep in mind APR doesn't always run as much boost as people think. Sometimes even less than the other competitors. Tuning goes beyond adding more boost and fuel, With the combination of being able unlock and control the VTG's and timing are the major keys to their programming upgrade.

 

Matthew, I sent you a pm.

 

pm replied

 

When a 997TT has APR flash,sport button does not raise boost level...it is always 1,0bar...APR achieves this tremendous amount of torque and hp ratings with very careful and unique tune of VTG maps combined with other variables such as timing advance and fuel trimming...But the main difference from other tunes is the way they tune VTGs...

 

Could you elaborate on what you mean by unique tune of vtg maps and fuel trim? Your getting significantly more power at lower boost than 700 kits with upgraded vtg turbos at higher boost. How can this be?

 

Its odd given the stock tune produces 620nms at 1 bar boost yet APR can deliver an additional 245nms without adding to the 1 bar boost.

TT my understanding of tunes is there are 3 basic components, fuel, timing and boost. So how APR's modification of the timing can produce this additional 245nms is worthy of a tuning "oscar" given Porsche has not managed anything anywhere near this figure.
Interestingly, Porsche also has chosen to increase the torque from 620nms to 680nms in Sports C mode by raising boost from 1 bar to 1.2 bar amongst other things im sure.
I have heard the timing in these engines is a very sensitive and critical component determining the reliability and life span particularly when different octane fuels are involved. Again im not saying in any way that the APR tune is a bad tune, just that there are way too many unanswered questions to make one feel comfortable that it is not seriously taxing the life out of the engine. Changing the pitch of the VTG's is usually done to change the boost and or bring higher boost at different rev ranges so, even to simply maintain the 1 bar over the entire rev range seems hard to believe that would make so much extra torques. For all anyone knows APR have just simply pegged the gauge electronically to read only 1 bar when in fact there is a lot more going on in the shadows. I still say 245nms is a hell of a lot of torque to produce without increasing boost.

Btw Skandalis hows your tip tranny holding up to all that torque? I recall you saying at one stage it slips?

 

If it looks too good to be true then....
Clearly it does an amazing job if the 6.5s 60-130 is true. I'm not expecting APR to tell us their secrets but if all they can say is basically "we're great and everyone else is a retard" then that's not good enough. (I know no-one has actually said that but reading between the lines, anytime a company can do significantly better than their competition for far less money it basically implies that). There are only so many variables to mess with in order to massively increase torque. If you can do it to an extent that upgraded turbos and intercoolers can't do from well known tuners then there's gotta be something up such as significant overdriving of the stock turbos etc... Again, this is just my opinion and should be taken as such.

 

This seems like a fair description of the risks involved with any tune. Has anyone run 100k miles with a tune? At some point something will happen, and inevitably with the added strain from any mod which produces more power, this will eventually cause more wear and premature repairs.
-Getz

 

Matt, perhaps you could ask APR to share some of the data they logged during testing?

 

Agree. How and why all the other tuners (including Porsche oem tuner) have all managed to miss out on this fantastic unique APR tuning method truly beggars belief!!

And, if it was so brilliant and unique you'd honestly think that the tuners would do what Nissan did with the development of the Gtr....afterall it would be in their best interest to do so. Nissan knew the 997tt was a special benchmark so they bought one and found out what made it tick and then made theirs faster.

What you say Getz is very true. Its just how much advice certain tuners are prepared to give you (or not give you) prior to customers embarking on their tune journey's that is the real worry here.
Transparency is a required necessity and its a shame we dont seem to be getting that all too frequently these days .

Fair question bbywu.

Afterall its not as if APR stand to miss out on anything more than the little business they are currently getting. In fact by providing some detail and, a bit of transparency, they actually stand to get a better business result.

Why someone high up in the food chain at APR hasnt taken advantage of the opportunity of this thread to chime in and provide some real tangible facts is astonishing.

 

getz.
I think that every tune gives more stress to engine...you say about 100kmiles...but who has done 100kmiles with a tune...I was much more hard believer than you of that performance before i bought this car...I had to drive it and see its times to believe it...If you want your engine to operate OEM...leave it stock...Otherwise if you add larger VTGs,tune,exhaust,boost...of course you add stress to the engine...My car has this flash for 15000km without any issue...(please dont say again cold start engine noise was from tune,i explained on another thread the reason and how to avoid this,but nobody seemed to care and comment...)
And finally to give this story an end,i do not work for APR and so i just share my thoughts and measured times with you guys...I dont see a reason for someone to write IF 6,48 for 60-130 is true...I sent file for verification and it was verified...I am really happy that no 997TT with a tune can pass me...It needs at least VTGs,intercoolers to be able to stand up...

 

Thanks for sharing everyone, interesting thread. Is it a bad idea just to have the APR tune with stock exhaust?

 

I've been on track with APR's own 996 and 997 Turbos, sometimes with Randy Pobst driving and neither of them seemed like anywhere near 6.5 60-130 cars.

If they can show me where they hit high 170's on the back straight at road atlanta (I've run 170 full weight with 996 TT K24's, tune, exhaust), I'd be a believer, but there is a video of their car running toe to toe with a GT-R that wasn't anywhere near a 6.5 car. Cars were equal on the straights.

I think some information is being left out here. In this vid they don't even hit 165.

http://www.youtube.com/watch?v=FvQwiVJcE3M